Exhumed by-pass margins of carbonate platforms from the Umbria-Marches Apennines, Italy

Conference · Tue Jan 01 00:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6577407

Bice, D M; Steward, K G

The recent discovery of portions of several by-pass margins in the Jurassic carbonates of the Umbria-marches Apennines allows a close look at the processes that create and shape this type of margin, which has eluded study in the past. These by-pass margins developed on the escarpments of large normal faults, which broke up a large carbonate platform into a group of smaller, isolated platforms. Sediment swept off the tops of these isolated platforms eroded a set of subparallel grooves into the marginal escarpments, and accumulated in coalescing cones at the bases of the escarpments. Bioclastic grainstones and packstones, including concentrations of large ammonite shells, and pebbly mudstones characterize these base-of-escarpment sediments. Subsidence during a time when there were few effective reef-building organisms led to the drowning of these isolated platforms. This drowning led to a change from by-pass margins with relief of up to 1 km. to depositional margins with decreasing relief as the basins filled.

• Research Organization: Univ. of California, Berkeley (USA)
• OSTI ID: 6577407
• Report Number(s): CONF-8510489-
• Journal Information: Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
ITALY
CARBONATE ROCKS
SEDIMENTARY BASINS
ALLUVIAL DEPOSITS
GEOLOGIC HISTORY
EROSION
GEOLOGIC FAULTS
JURASSIC PERIOD
LITHOLOGY
SEDIMENTS
EUROPE
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
MESOZOIC ERA
ROCKS
SEDIMENTARY ROCKS
WESTERN EUROPE
580100* - Geology & Hydrology- (-1989)